Why is ether used as the primary extraction solvent in Experiment015 ?
From the log of Exp015:
19:13] Poured solution without excess NaCl into a separatory funnel. Extracted with 17mL anhydrous ether
19:20] Extracted with 10mL anhydrous ether
19:24] Extracted with 10mL ether
(The follow information is collected from this site and this site )
The most common way to extract dissolved substances from aqueous solutions is by the almost water-insoluble solvents
- An important intermediate product in the Ugi synthesis of diketopiparzine antimalarial targets is DOPAL.
- Despite reasoning to believe that DOPAL was soluble in methylene chloride (from reported purification of DOPAL using cholorform in hexanes) , it was seen that adrenaline bases were not that soluble in chlorinated solvents.
- Ether, however, was an optimal solvent for DOPAL was extracted in it.
- Illustrating ether’s properties as being an excellent extraction solvent, it was used greatly in this experiment
- Readily removed by evaporation, it is best to use in a product which has a relatively low boiling point.
- Ether molecules, weakly basic compounds, are used over dichloromethane due to varying physical properties of each compound
- Being an immiscible solvent, it easily forms two layers in the separatory funnel so as to make the extraction much easier.
- Since their carbon-oxygen bonds are not readily detached, ethers are fairly unreactive compounds
- Thus, they are frequently used over dichloromethane due to the fact that so many neutral organic compounds are soluble in it
- In addition, dichloromethane is not highly soluble in water, which would not make for an optimal extraction solvent the opposite is true - that makes dichloromethane a good extraction solvent as well
- For example, at 20 degrees, diethyl ether is soluble to extent of 6.9g in 100ml of water
- Dicholormethane, on the other hand, is less soluble and is only soluble 1.3 g in 100mL at 20 degrees
- Another disadvantage is that after a long period of time the vapors of the dicholormethan become dangerous
- The solution of glycerol, phosphoric acid, and NACL, which is being extracted best responds to the properties of ether and thus result in a better separation scheme than dichloromethane
- The slightly polar C-O-C bond in the functional group of the ether causes for a better solvent as compared to the nonpolar dichloromethane
- Dicholormethan is nonpolar due to the fact that carbon shares the hydrogen molecules uniformly. wrong dichloromethane is polar - see p. 12 of the pdf fromthis lecture
- Also the two chlorine molecules cancel out each other's polarity and leaves the molecule in a symmetrical fashion. ( with no associated polarity)
- The presence of two lone pairs of electrons on the oxygen atoms makes hydrogen bonding with water molecules possible, which is not possible in dichloromethane
( The solubility properties of polar and nonpolar substances along with their bonding patterns playing roles in solubility have been seein in Lecture 07.)
From the log of Exp015:
19:13] Poured solution without excess NaCl into a separatory funnel. Extracted with 17mL anhydrous ether
19:20] Extracted with 10mL anhydrous ether
19:24] Extracted with 10mL ether
(The follow information is collected from this site and this site )
The most common way to extract dissolved substances from aqueous solutions is by the almost water-insoluble solvents
- An important intermediate product in the Ugi synthesis of diketopiparzine antimalarial targets is DOPAL.
- Despite reasoning to believe that DOPAL was soluble in methylene chloride (from reported purification of DOPAL using cholorform in hexanes) , it was seen that adrenaline bases were not that soluble in chlorinated solvents.
- Ether, however, was an optimal solvent for DOPAL was extracted in it.
- Illustrating ether’s properties as being an excellent extraction solvent, it was used greatly in this experiment
- Readily removed by evaporation, it is best to use in a product which has a relatively low boiling point.
- Ether molecules, weakly basic compounds, are used over dichloromethane due to varying physical properties of each compound
- Being an immiscible solvent, it easily forms two layers in the separatory funnel so as to make the extraction much easier.
- Since their carbon-oxygen bonds are not readily detached, ethers are fairly unreactive compounds
- Thus, they are frequently used over dichloromethane due to the fact that so many neutral organic compounds are soluble in it
- In addition, dichloromethane is not highly soluble in water, which would not make for an optimal extraction solvent the opposite is true - that makes dichloromethane a good extraction solvent as well
- For example, at 20 degrees, diethyl ether is soluble to extent of 6.9g in 100ml of water
- Dicholormethane, on the other hand, is less soluble and is only soluble 1.3 g in 100mL at 20 degrees
- Another disadvantage is that after a long period of time the vapors of the dicholormethan become dangerous
- The solution of glycerol, phosphoric acid, and NACL, which is being extracted best responds to the properties of ether and thus result in a better separation scheme than dichloromethane
- The slightly polar C-O-C bond in the functional group of the ether causes for a better solvent as compared to the nonpolar dichloromethane
- Dicholormethan is nonpolar due to the fact that carbon shares the hydrogen molecules uniformly. wrong dichloromethane is polar - see p. 12 of the pdf from this lecture
- Also the two chlorine molecules cancel out each other's polarity and leaves the molecule in a symmetrical fashion. ( with no associated polarity)
- The presence of two lone pairs of electrons on the oxygen atoms makes hydrogen bonding with water molecules possible, which is not possible in dichloromethane
( The solubility properties of polar and nonpolar substances along with their bonding patterns playing roles in solubility have been seein in Lecture 07.)
Diagram of Ether Molecule:
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Grade: 7/10